First article in a series by Ralph Griswold on using cellular automata to generate drawdown patterns for weaving. It introduces cellular automata geometries, two-state square cells, von Neumann and Moore neighborhoods, and transition rules such as the parity rule, voter rule and the 1-of-8 rule. It also covers edge wraparound (torus topology), pattern sequences started from seeds or symmetric patterns, and the structural and aesthetic problems of choosing usable patterns. It ends with resources, references and a large 65x65 1-of-8 pattern.